Alex Reyes has been the Cardinals best prospect for 4 years running. In 2020, Alex Reyes will not be the top prospect in the Cardinals' organization. Once he records ONE OUT this year, he will no longer be considered a rookie by MLB standards. Therefore, he could win MLB Rookie of the Year for the NL in 2019, potentially. Of course, the Cardinals have him relieving this year. I don't say "of course" to bash the Cardinals there. There's a much longer back story.
The TL;DR version of that back story is that Reyes came up as a reliever in 2016. He relieved in 5 games with a win, a save, and a hold. He also had 13 strikeouts in under 10 innings with only 9 men reaching base and an OPS against of under .500. The team then started him in two games in which he recorded over 10 innings with a sub-.575 OPS against and over a K an inning again. The team shoved him back into a long relief role in which he again excelled. Then they asked him to start again for his final 3 games of the season. All in all, he threw 46 major league innings in 2016 and they were damn good.
Then, the day he arrived to spring training in 2017, he was put on the DL for the year with Tommy John surgery. He recovered from that surgery in an appropriate amount of time and when getting back to pitching in the middle of 2018 in the minors, he was maybe the best he ever looked. He threw one start in A ball, one in High A, one in AA, and one in AAA on his way back to the majors. In those 4 starts, he threw a total of:
23 innings (5.75 IP/start - the last two were 7 2/3 innings and 7 innings as he built his arm strength back up)
44 strikeouts (THAT'S A 53.7% K RATE!?!?!?!)
7 BB (8.5% BB rate)
7 hits allowed (.085 batting average against)
1 wild pitch
He then came up to the majors, looking to be the savior of the Cardinals' season as they were 29-23, but in just 3rd place in the division and 4 games back. He threw 4 innings of 3 hit ball (2 Ks, 2 BBs, 1 HBP) but just facing 3 over the minimum. He then hit the DL again with an oblique injury.
The Cardinals will keep him on a pitch and innings count this year and hope to keep the innings down earlier in the year making sure he is healthy and good to go by keeping him as a RP early on in 2019.
His final spring numbers this year ended with him getting 8 innings over 7 games. He only gave up 4 hits, but walked 6 (giving up 1 HR). He struck out 8 of the 33 batters he faced.
Reyes has a PLUS PLUS fastball, a PLUS curve ball, a PLUS slider, and a PLUS change up. I mean, the dude is made for a top of the rotation. His command is likely a sub-50 grade command, but that can be built upon.
His best pitch is his fastball, but look at these two pitches in conjunction with one another and then imagine them coming in the same plate appearance as a 97-101 mph fastball. The yellow is a slider and the blue is the change up. They might be his 3rd and 4th best pitches. This minor leaguer batting against him didn't stand a chance.
(@cardinalsgifs on the helper there and in the cover art. Thanks, gifs!)
On to what you're here for...here is what a typical RP has done per 60 games over last 5 seasons:
Much like what I did with John Gant, I am going to do here with Reyes. I am projecting Reyes for 100 innings. My guess is that not all of these will be in relief, however the numbers I am going to give you are solely as a reliever. The numbers will be worse as a starter, most likely. That's how it works in baseball.
Here is what I have projected for Alex Reyes' 2019 season:
100 innings pitched
3.06 ERA, 2.35 FIP, 1.360 WHIP, 2.83 K:BB
7.470 H/9, 13.500 K/9, 4.700 BB/9, 0.360 HR/9
What can be pointed out to show that things CAN be better than that?!?
Did you see his 3rd and 4th best pitches above? The curve ball looks like Bugs Bunny threw it and the fastball looks like a 75mm diameter spherical train coming towards the catcher at 97+ mph. He could be starting for more of those innings...I'd say up to 120 or so would be the max this season. 150-160 in 2020. Full starters' load thereafter.
How/If things go wrong:
If things go wrong, Alex Reyes is injured and is never "right" again. Period. That's the only way it goes wrong.